1. Field of the Invention
The present invention relates to a radiant heat control apparatus for an automotive vehicle, which can control the amount of radiant heat transferred between vehicle body inner surfaces and passengers within an optimum range.
2. Description of the Prior Art
The effect of the radiant heat control apparatus will be described with reference to FIGS. 1(A) and (B).
In FIGS. 1(A) and (B), a vehicle passenger M takes a seat enclosed by the inner surface S of a vehicle body such as a roof 1, side windshields 2, doors 3, a floor panel 4, etc. Therefore, radiant heat is transferred between the passenger M and the vehicle body inner surface S according to a difference in temperature between the two.
In winter, for instance, since the external temperature is low and therefore the vehicle inner surface S is cold, even if temperature within the passenger compartment is kept at a constant warm temperature by an air conditioner, radiant heat is transferred from the skin of the passenger M to the vehicle body inner surface S (called negative radiation (N), so that the passenger M feels cold because radiant heat is radiated from the passenger M, as shown in FIG. 1(A). On the other hand, in summer, since the external temperature is high and therefore the vehicle body inner surface S is hot, even if temperature within the passenger compartment is kept at a constant cool temperature by an air conditioner, radiant heat is transferred from the vehicle body inner surface S to the passenger M (called positive radiation P), so that the passenger M feels hot because radiant heat is applied to the passenger M, as shown in FIG. 1(B).
To overcome the above-mentioned problem, Japanese Published Unexamined (Kokai) Utility Model Application No. 61-61220 discloses heat generators 5 disposed within the side doors 3 as shown in FIG. 2(A) in order to change the negative radiation N as shown in FIG. 1(A) to the positive radiation P as shown in FIG. 1(B) between the passenger M and the vehicle body inner surface S. In the prior-art radiant heat control apparatus, however, since the heat generators 5 are simply turned on or off to heat only the vehicle door inner surface S, it has been impossible to comfortably control radiant heat transferred between the passenger and the vehicle inner surface.